The present invention relates to waveform display instruments, and more particularly to a method for controlling zoom of a waveform display using a touch screen as an interaction control.
In conventional waveform monitoring equipment, such as oscilloscopes and television waveform monitors, a waveform display is controlled by a gain and a position control in each of the x and y axes. This requires four knobs, and the interaction between the gains and offsets is usually awkward. Changing the gain generally requires changing the offset, or position, to keep a certain point of the waveform on the display.
What is desired is a method for controlling the gain of a waveform about a given point on the waveform without the necessity of adjusting the offset to keep the given point on the display screen.